1. Field of the invention.
The present invention relates to mud pumps of the triplex-type which are used in conjunction with a rotary oil well drilling operation to pump a mud mixture down through the drill pipe for removing drilled earth formations.
Pumps of this character have three cylinders in which each cylinder includes a piston reciprocated by a piston rod. The cylinder communicates with suction and discharge valve equipped chambers so that, as the piston is reciprocated by the piston rod, drilling fluid will be alternately drawn into and discharged from the working chambers. Since the material pumped is of an abrasive character, the wear on the piston and cylinder wall is quite severe and it has been common practice, in order to more easily repair a worn pump, to provide each cylinder with a replaceable steel liner which reciprocably supports the piston in the cylinder, however, as mentioned above, the abrasive drilling fluid results in a relatively short life for the liner and piston.
This invention tends to reduce the liner and piston wear by cleaning the liner and piston during pump operation.
2. Description of the prior art.
Prior patents generally relate to seals between the liner and cylinder walls and between the piston and liner in which the life of the seals is lengthened by forming fluid channels through the piston rod and piston between its end seals for conducting oil and/or water to lubricate the seals and reduce the abrasive action of the drilling mud particles.
This invention approaches the liner and piston wear problem from a different standpoint, namely, by washing drilling mud abrasive particles off the liner in the path of movement of the piston therein which is accomplished by providing conductors supported by the liner and applying streams of water to the bore of the liner and surface of the piston.